The Detroit Now and Then project combines vintage photos of the city with images of what’s there now, providing a poignant reminder of what the city was, what it is now and--maybe--what it could be again.

If Portlandia were a photo series, it would probably look something like Kirk Crippens’s "Portraitlandia," which features iconic Rose City residents in their natural habitats.

We brought together some of the most interesting urban thinkers to play the new version of Sim City to see who would make the best fake metropolis. But building a sustainable city from the ground up is harder than it looks.

Cities are so ... static. The Very Large Structure will let an urban population just roll down the road if commerce or resources dry up.

In Darkened Cities, the lights from these famous metropolises have been removed, giving you a glimpse at what a city would look like without the power of electricity.

These charts--made with information from weather satellites scanning the ground--show how wide and how tall cities around the world have grown. What’s happening to the size of cities in Asia will blow your mind.

Before Apple began work on its massive new headquarters, one architect took it upon himself to design an alternative for Steve Jobs: a walkable, livable city anchored by the company’s offices.

The new book, A History of Future Cities, looks at the attempts of places like Dubai, Shanghai, and Mumbai to create Western-looking areas in an attempt to create a sense of modernity.

As scientists make huge strides in robotics, natural building materials, and new construction methods, our urban architecture could take on a much different form than the rigid construction we’re used to.

100 Ideas To Improve New York City's subway: Because every public transportation station could use some skylights and odor detectors.

Manhattan has one of the worst income gaps of any city--or country--in the world, often separated by just a few blocks. These striking graphics make that inequality apparent in the height of the city's buildings.

For many urban residents, their city is a source of identity and pride. But 2013 has been a rough year for many cities and their denizens. In New York, San Francisco, and other urban centers, income inequality—the gap between the richest and poorest residents—is on the rise as the costs of living soar while wages and job growth stagnate. And Detroit, a city in decline for decades, was forced to take the unprecedented step (for a city of its size) of filing for bankruptcy in July.

Yet from bad situations are often exactly where good ideas and innovation spring. Detroit, for example, has become a hub of experimentation in everything from urban farming to creative photography to entrepreneurship. And we’ve seen a steady flow of impressive ideas on how to create a more sustainable and affordable life for all of a city’s residents. Innovative low-cost construction methods could make housing easier and cheaper to build, while a 600-foot-tall city on wheels that can move around when resources dry up was one of the wackier proposals.

Another trend we’ve seen is the continued rise of the "megacity," a city with more than 10 million inhabitants. By 2050, 7 out of every 10 people on Earth is projected to live in a city, and many will horde to dense urban hubs from Dubai to Mumbai. The U.S.’s urban centers may matter less and less in the future.

The Detroit "Now and Then" project artfully combined vintage photos of the city with images of what’s there now, providing a poignant reminder of what the city was, what it is now and—maybe—what it could be again.

We brought together some of the most interesting urban thinkers to play the new version of the city planning game to see who would make the best fake metropolis. But building a sustainable city from the ground up is harder than it looks.

These charts—made with information from weather satellites scanning the ground—show how wide and how tall cities around the world have grown. What’s happening to the size of cities in Asia will blow your mind.

As scientists make huge strides in robotics, natural building materials, and new construction methods, our urban architecture could take on a much different form than the rigid construction we’re used to.

Manhattan has one of the worst income gaps of any city—or country—in the world, often separated by just a few blocks. These striking graphics make that inequality apparent in the height of the city's buildings.